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lauxlib.c 31 KB

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  1. /*
  2. ** $Id: lauxlib.c $
  3. ** Auxiliary functions for building Lua libraries
  4. ** See Copyright Notice in lua.h
  5. */
  6. #define lauxlib_c
  7. #define LUA_LIB
  8. #include "lprefix.h"
  9. #include <errno.h>
  10. #include <stdarg.h>
  11. #include <stdio.h>
  12. #include <stdlib.h>
  13. #include <string.h>
  14. /*
  15. ** This file uses only the official API of Lua.
  16. ** Any function declared here could be written as an application function.
  17. */
  18. #include "lua.h"
  19. #include "lauxlib.h"
  20. #if !defined(MAX_SIZET)
  21. /* maximum value for size_t */
  22. #define MAX_SIZET ((size_t)(~(size_t)0))
  23. #endif
  24. /*
  25. ** {======================================================
  26. ** Traceback
  27. ** =======================================================
  28. */
  29. #define LEVELS1 10 /* size of the first part of the stack */
  30. #define LEVELS2 11 /* size of the second part of the stack */
  31. /*
  32. ** Search for 'objidx' in table at index -1. ('objidx' must be an
  33. ** absolute index.) Return 1 + string at top if it found a good name.
  34. */
  35. static int findfield (lua_State *L, int objidx, int level) {
  36. if (level == 0 || !lua_istable(L, -1))
  37. return 0; /* not found */
  38. lua_pushnil(L); /* start 'next' loop */
  39. while (lua_next(L, -2)) { /* for each pair in table */
  40. if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */
  41. if (lua_rawequal(L, objidx, -1)) { /* found object? */
  42. lua_pop(L, 1); /* remove value (but keep name) */
  43. return 1;
  44. }
  45. else if (findfield(L, objidx, level - 1)) { /* try recursively */
  46. /* stack: lib_name, lib_table, field_name (top) */
  47. lua_pushliteral(L, "."); /* place '.' between the two names */
  48. lua_replace(L, -3); /* (in the slot occupied by table) */
  49. lua_concat(L, 3); /* lib_name.field_name */
  50. return 1;
  51. }
  52. }
  53. lua_pop(L, 1); /* remove value */
  54. }
  55. return 0; /* not found */
  56. }
  57. /*
  58. ** Search for a name for a function in all loaded modules
  59. */
  60. static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
  61. int top = lua_gettop(L);
  62. lua_getinfo(L, "f", ar); /* push function */
  63. lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
  64. if (findfield(L, top + 1, 2)) {
  65. const char *name = lua_tostring(L, -1);
  66. if (strncmp(name, LUA_GNAME ".", 3) == 0) { /* name start with '_G.'? */
  67. lua_pushstring(L, name + 3); /* push name without prefix */
  68. lua_remove(L, -2); /* remove original name */
  69. }
  70. lua_copy(L, -1, top + 1); /* copy name to proper place */
  71. lua_settop(L, top + 1); /* remove table "loaded" and name copy */
  72. return 1;
  73. }
  74. else {
  75. lua_settop(L, top); /* remove function and global table */
  76. return 0;
  77. }
  78. }
  79. static void pushfuncname (lua_State *L, lua_Debug *ar) {
  80. if (pushglobalfuncname(L, ar)) { /* try first a global name */
  81. lua_pushfstring(L, "function '%s'", lua_tostring(L, -1));
  82. lua_remove(L, -2); /* remove name */
  83. }
  84. else if (*ar->namewhat != '\0') /* is there a name from code? */
  85. lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name); /* use it */
  86. else if (*ar->what == 'm') /* main? */
  87. lua_pushliteral(L, "main chunk");
  88. else if (*ar->what != 'C') /* for Lua functions, use <file:line> */
  89. lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
  90. else /* nothing left... */
  91. lua_pushliteral(L, "?");
  92. }
  93. static int lastlevel (lua_State *L) {
  94. lua_Debug ar;
  95. int li = 1, le = 1;
  96. /* find an upper bound */
  97. while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }
  98. /* do a binary search */
  99. while (li < le) {
  100. int m = (li + le)/2;
  101. if (lua_getstack(L, m, &ar)) li = m + 1;
  102. else le = m;
  103. }
  104. return le - 1;
  105. }
  106. LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
  107. const char *msg, int level) {
  108. luaL_Buffer b;
  109. lua_Debug ar;
  110. int last = lastlevel(L1);
  111. int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
  112. luaL_buffinit(L, &b);
  113. if (msg) {
  114. luaL_addstring(&b, msg);
  115. luaL_addchar(&b, '\n');
  116. }
  117. luaL_addstring(&b, "stack traceback:");
  118. while (lua_getstack(L1, level++, &ar)) {
  119. if (limit2show-- == 0) { /* too many levels? */
  120. int n = last - level - LEVELS2 + 1; /* number of levels to skip */
  121. lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n);
  122. luaL_addvalue(&b); /* add warning about skip */
  123. level += n; /* and skip to last levels */
  124. }
  125. else {
  126. lua_getinfo(L1, "Slnt", &ar);
  127. if (ar.currentline <= 0)
  128. lua_pushfstring(L, "\n\t%s: in ", ar.short_src);
  129. else
  130. lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline);
  131. luaL_addvalue(&b);
  132. pushfuncname(L, &ar);
  133. luaL_addvalue(&b);
  134. if (ar.istailcall)
  135. luaL_addstring(&b, "\n\t(...tail calls...)");
  136. }
  137. }
  138. luaL_pushresult(&b);
  139. }
  140. /* }====================================================== */
  141. /*
  142. ** {======================================================
  143. ** Error-report functions
  144. ** =======================================================
  145. */
  146. LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {
  147. lua_Debug ar;
  148. if (!lua_getstack(L, 0, &ar)) /* no stack frame? */
  149. return luaL_error(L, "bad argument #%d (%s)", arg, extramsg);
  150. lua_getinfo(L, "n", &ar);
  151. if (strcmp(ar.namewhat, "method") == 0) {
  152. arg--; /* do not count 'self' */
  153. if (arg == 0) /* error is in the self argument itself? */
  154. return luaL_error(L, "calling '%s' on bad self (%s)",
  155. ar.name, extramsg);
  156. }
  157. if (ar.name == NULL)
  158. ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?";
  159. return luaL_error(L, "bad argument #%d to '%s' (%s)",
  160. arg, ar.name, extramsg);
  161. }
  162. int luaL_typeerror (lua_State *L, int arg, const char *tname) {
  163. const char *msg;
  164. const char *typearg; /* name for the type of the actual argument */
  165. if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
  166. typearg = lua_tostring(L, -1); /* use the given type name */
  167. else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA)
  168. typearg = "light userdata"; /* special name for messages */
  169. else
  170. typearg = luaL_typename(L, arg); /* standard name */
  171. msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg);
  172. return luaL_argerror(L, arg, msg);
  173. }
  174. static void tag_error (lua_State *L, int arg, int tag) {
  175. luaL_typeerror(L, arg, lua_typename(L, tag));
  176. }
  177. /*
  178. ** The use of 'lua_pushfstring' ensures this function does not
  179. ** need reserved stack space when called.
  180. */
  181. LUALIB_API void luaL_where (lua_State *L, int level) {
  182. lua_Debug ar;
  183. if (lua_getstack(L, level, &ar)) { /* check function at level */
  184. lua_getinfo(L, "Sl", &ar); /* get info about it */
  185. if (ar.currentline > 0) { /* is there info? */
  186. lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
  187. return;
  188. }
  189. }
  190. lua_pushfstring(L, ""); /* else, no information available... */
  191. }
  192. /*
  193. ** Again, the use of 'lua_pushvfstring' ensures this function does
  194. ** not need reserved stack space when called. (At worst, it generates
  195. ** an error with "stack overflow" instead of the given message.)
  196. */
  197. LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
  198. va_list argp;
  199. va_start(argp, fmt);
  200. luaL_where(L, 1);
  201. lua_pushvfstring(L, fmt, argp);
  202. va_end(argp);
  203. lua_concat(L, 2);
  204. return lua_error(L);
  205. }
  206. LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
  207. int en = errno; /* calls to Lua API may change this value */
  208. if (stat) {
  209. lua_pushboolean(L, 1);
  210. return 1;
  211. }
  212. else {
  213. luaL_pushfail(L);
  214. if (fname)
  215. lua_pushfstring(L, "%s: %s", fname, strerror(en));
  216. else
  217. lua_pushstring(L, strerror(en));
  218. lua_pushinteger(L, en);
  219. return 3;
  220. }
  221. }
  222. #if !defined(l_inspectstat) /* { */
  223. #if defined(LUA_USE_POSIX)
  224. #include <sys/wait.h>
  225. /*
  226. ** use appropriate macros to interpret 'pclose' return status
  227. */
  228. #define l_inspectstat(stat,what) \
  229. if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \
  230. else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }
  231. #else
  232. #define l_inspectstat(stat,what) /* no op */
  233. #endif
  234. #endif /* } */
  235. LUALIB_API int luaL_execresult (lua_State *L, int stat) {
  236. if (stat != 0 && errno != 0) /* error with an 'errno'? */
  237. return luaL_fileresult(L, 0, NULL);
  238. else {
  239. const char *what = "exit"; /* type of termination */
  240. l_inspectstat(stat, what); /* interpret result */
  241. if (*what == 'e' && stat == 0) /* successful termination? */
  242. lua_pushboolean(L, 1);
  243. else
  244. luaL_pushfail(L);
  245. lua_pushstring(L, what);
  246. lua_pushinteger(L, stat);
  247. return 3; /* return true/fail,what,code */
  248. }
  249. }
  250. /* }====================================================== */
  251. /*
  252. ** {======================================================
  253. ** Userdata's metatable manipulation
  254. ** =======================================================
  255. */
  256. LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
  257. if (luaL_getmetatable(L, tname) != LUA_TNIL) /* name already in use? */
  258. return 0; /* leave previous value on top, but return 0 */
  259. lua_pop(L, 1);
  260. lua_createtable(L, 0, 2); /* create metatable */
  261. lua_pushstring(L, tname);
  262. lua_setfield(L, -2, "__name"); /* metatable.__name = tname */
  263. lua_pushvalue(L, -1);
  264. lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */
  265. return 1;
  266. }
  267. LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) {
  268. luaL_getmetatable(L, tname);
  269. lua_setmetatable(L, -2);
  270. }
  271. LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) {
  272. void *p = lua_touserdata(L, ud);
  273. if (p != NULL) { /* value is a userdata? */
  274. if (lua_getmetatable(L, ud)) { /* does it have a metatable? */
  275. luaL_getmetatable(L, tname); /* get correct metatable */
  276. if (!lua_rawequal(L, -1, -2)) /* not the same? */
  277. p = NULL; /* value is a userdata with wrong metatable */
  278. lua_pop(L, 2); /* remove both metatables */
  279. return p;
  280. }
  281. }
  282. return NULL; /* value is not a userdata with a metatable */
  283. }
  284. LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
  285. void *p = luaL_testudata(L, ud, tname);
  286. luaL_argexpected(L, p != NULL, ud, tname);
  287. return p;
  288. }
  289. /* }====================================================== */
  290. /*
  291. ** {======================================================
  292. ** Argument check functions
  293. ** =======================================================
  294. */
  295. LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
  296. const char *const lst[]) {
  297. const char *name = (def) ? luaL_optstring(L, arg, def) :
  298. luaL_checkstring(L, arg);
  299. int i;
  300. for (i=0; lst[i]; i++)
  301. if (strcmp(lst[i], name) == 0)
  302. return i;
  303. return luaL_argerror(L, arg,
  304. lua_pushfstring(L, "invalid option '%s'", name));
  305. }
  306. /*
  307. ** Ensures the stack has at least 'space' extra slots, raising an error
  308. ** if it cannot fulfill the request. (The error handling needs a few
  309. ** extra slots to format the error message. In case of an error without
  310. ** this extra space, Lua will generate the same 'stack overflow' error,
  311. ** but without 'msg'.)
  312. */
  313. LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
  314. if (!lua_checkstack(L, space)) {
  315. if (msg)
  316. luaL_error(L, "stack overflow (%s)", msg);
  317. else
  318. luaL_error(L, "stack overflow");
  319. }
  320. }
  321. LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) {
  322. if (lua_type(L, arg) != t)
  323. tag_error(L, arg, t);
  324. }
  325. LUALIB_API void luaL_checkany (lua_State *L, int arg) {
  326. if (lua_type(L, arg) == LUA_TNONE)
  327. luaL_argerror(L, arg, "value expected");
  328. }
  329. LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) {
  330. const char *s = lua_tolstring(L, arg, len);
  331. if (!s) tag_error(L, arg, LUA_TSTRING);
  332. return s;
  333. }
  334. LUALIB_API const char *luaL_optlstring (lua_State *L, int arg,
  335. const char *def, size_t *len) {
  336. if (lua_isnoneornil(L, arg)) {
  337. if (len)
  338. *len = (def ? strlen(def) : 0);
  339. return def;
  340. }
  341. else return luaL_checklstring(L, arg, len);
  342. }
  343. LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) {
  344. int isnum;
  345. lua_Number d = lua_tonumberx(L, arg, &isnum);
  346. if (!isnum)
  347. tag_error(L, arg, LUA_TNUMBER);
  348. return d;
  349. }
  350. LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) {
  351. return luaL_opt(L, luaL_checknumber, arg, def);
  352. }
  353. static void interror (lua_State *L, int arg) {
  354. if (lua_isnumber(L, arg))
  355. luaL_argerror(L, arg, "number has no integer representation");
  356. else
  357. tag_error(L, arg, LUA_TNUMBER);
  358. }
  359. LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) {
  360. int isnum;
  361. lua_Integer d = lua_tointegerx(L, arg, &isnum);
  362. if (!isnum) {
  363. interror(L, arg);
  364. }
  365. return d;
  366. }
  367. LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg,
  368. lua_Integer def) {
  369. return luaL_opt(L, luaL_checkinteger, arg, def);
  370. }
  371. /* }====================================================== */
  372. /*
  373. ** {======================================================
  374. ** Generic Buffer manipulation
  375. ** =======================================================
  376. */
  377. /* userdata to box arbitrary data */
  378. typedef struct UBox {
  379. void *box;
  380. size_t bsize;
  381. } UBox;
  382. static void *resizebox (lua_State *L, int idx, size_t newsize) {
  383. void *ud;
  384. lua_Alloc allocf = lua_getallocf(L, &ud);
  385. UBox *box = (UBox *)lua_touserdata(L, idx);
  386. void *temp = allocf(ud, box->box, box->bsize, newsize);
  387. if (temp == NULL && newsize > 0) { /* allocation error? */
  388. lua_pushliteral(L, "not enough memory");
  389. lua_error(L); /* raise a memory error */
  390. }
  391. box->box = temp;
  392. box->bsize = newsize;
  393. return temp;
  394. }
  395. static int boxgc (lua_State *L) {
  396. resizebox(L, 1, 0);
  397. return 0;
  398. }
  399. static const luaL_Reg boxmt[] = { /* box metamethods */
  400. {"__gc", boxgc},
  401. {"__close", boxgc},
  402. {NULL, NULL}
  403. };
  404. static void newbox (lua_State *L) {
  405. UBox *box = (UBox *)lua_newuserdatauv(L, sizeof(UBox), 0);
  406. box->box = NULL;
  407. box->bsize = 0;
  408. if (luaL_newmetatable(L, "_UBOX*")) /* creating metatable? */
  409. luaL_setfuncs(L, boxmt, 0); /* set its metamethods */
  410. lua_setmetatable(L, -2);
  411. }
  412. /*
  413. ** check whether buffer is using a userdata on the stack as a temporary
  414. ** buffer
  415. */
  416. #define buffonstack(B) ((B)->b != (B)->init.b)
  417. /*
  418. ** Compute new size for buffer 'B', enough to accommodate extra 'sz'
  419. ** bytes.
  420. */
  421. static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
  422. size_t newsize = B->size * 2; /* double buffer size */
  423. if (MAX_SIZET - sz < B->n) /* overflow in (B->n + sz)? */
  424. return luaL_error(B->L, "buffer too large");
  425. if (newsize < B->n + sz) /* double is not big enough? */
  426. newsize = B->n + sz;
  427. return newsize;
  428. }
  429. /*
  430. ** Returns a pointer to a free area with at least 'sz' bytes in buffer
  431. ** 'B'. 'boxidx' is the relative position in the stack where the
  432. ** buffer's box is or should be.
  433. */
  434. static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {
  435. if (B->size - B->n >= sz) /* enough space? */
  436. return B->b + B->n;
  437. else {
  438. lua_State *L = B->L;
  439. char *newbuff;
  440. size_t newsize = newbuffsize(B, sz);
  441. /* create larger buffer */
  442. if (buffonstack(B)) /* buffer already has a box? */
  443. newbuff = (char *)resizebox(L, boxidx, newsize); /* resize it */
  444. else { /* no box yet */
  445. lua_pushnil(L); /* reserve slot for final result */
  446. newbox(L); /* create a new box */
  447. /* move box (and slot) to its intended position */
  448. lua_rotate(L, boxidx - 1, 2);
  449. lua_toclose(L, boxidx);
  450. newbuff = (char *)resizebox(L, boxidx, newsize);
  451. memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */
  452. }
  453. B->b = newbuff;
  454. B->size = newsize;
  455. return newbuff + B->n;
  456. }
  457. }
  458. /*
  459. ** returns a pointer to a free area with at least 'sz' bytes
  460. */
  461. LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
  462. return prepbuffsize(B, sz, -1);
  463. }
  464. LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
  465. if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */
  466. char *b = prepbuffsize(B, l, -1);
  467. memcpy(b, s, l * sizeof(char));
  468. luaL_addsize(B, l);
  469. }
  470. }
  471. LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
  472. luaL_addlstring(B, s, strlen(s));
  473. }
  474. LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
  475. lua_State *L = B->L;
  476. lua_pushlstring(L, B->b, B->n);
  477. if (buffonstack(B)) {
  478. lua_copy(L, -1, -3); /* move string to reserved slot */
  479. lua_pop(L, 2); /* pop string and box (closing the box) */
  480. }
  481. }
  482. LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
  483. luaL_addsize(B, sz);
  484. luaL_pushresult(B);
  485. }
  486. /*
  487. ** 'luaL_addvalue' is the only function in the Buffer system where the
  488. ** box (if existent) is not on the top of the stack. So, instead of
  489. ** calling 'luaL_addlstring', it replicates the code using -2 as the
  490. ** last argument to 'prepbuffsize', signaling that the box is (or will
  491. ** be) bellow the string being added to the buffer. (Box creation can
  492. ** trigger an emergency GC, so we should not remove the string from the
  493. ** stack before we have the space guaranteed.)
  494. */
  495. LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
  496. lua_State *L = B->L;
  497. size_t len;
  498. const char *s = lua_tolstring(L, -1, &len);
  499. char *b = prepbuffsize(B, len, -2);
  500. memcpy(b, s, len * sizeof(char));
  501. luaL_addsize(B, len);
  502. lua_pop(L, 1); /* pop string */
  503. }
  504. LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
  505. B->L = L;
  506. B->b = B->init.b;
  507. B->n = 0;
  508. B->size = LUAL_BUFFERSIZE;
  509. }
  510. LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
  511. luaL_buffinit(L, B);
  512. return prepbuffsize(B, sz, -1);
  513. }
  514. /* }====================================================== */
  515. /*
  516. ** {======================================================
  517. ** Reference system
  518. ** =======================================================
  519. */
  520. /* index of free-list header */
  521. #define freelist 0
  522. LUALIB_API int luaL_ref (lua_State *L, int t) {
  523. int ref;
  524. if (lua_isnil(L, -1)) {
  525. lua_pop(L, 1); /* remove from stack */
  526. return LUA_REFNIL; /* 'nil' has a unique fixed reference */
  527. }
  528. t = lua_absindex(L, t);
  529. lua_rawgeti(L, t, freelist); /* get first free element */
  530. ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */
  531. lua_pop(L, 1); /* remove it from stack */
  532. if (ref != 0) { /* any free element? */
  533. lua_rawgeti(L, t, ref); /* remove it from list */
  534. lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */
  535. }
  536. else /* no free elements */
  537. ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */
  538. lua_rawseti(L, t, ref);
  539. return ref;
  540. }
  541. LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
  542. if (ref >= 0) {
  543. t = lua_absindex(L, t);
  544. lua_rawgeti(L, t, freelist);
  545. lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */
  546. lua_pushinteger(L, ref);
  547. lua_rawseti(L, t, freelist); /* t[freelist] = ref */
  548. }
  549. }
  550. /* }====================================================== */
  551. /*
  552. ** {======================================================
  553. ** Load functions
  554. ** =======================================================
  555. */
  556. typedef struct LoadF {
  557. int n; /* number of pre-read characters */
  558. FILE *f; /* file being read */
  559. char buff[BUFSIZ]; /* area for reading file */
  560. } LoadF;
  561. static const char *getF (lua_State *L, void *ud, size_t *size) {
  562. LoadF *lf = (LoadF *)ud;
  563. (void)L; /* not used */
  564. if (lf->n > 0) { /* are there pre-read characters to be read? */
  565. *size = lf->n; /* return them (chars already in buffer) */
  566. lf->n = 0; /* no more pre-read characters */
  567. }
  568. else { /* read a block from file */
  569. /* 'fread' can return > 0 *and* set the EOF flag. If next call to
  570. 'getF' called 'fread', it might still wait for user input.
  571. The next check avoids this problem. */
  572. if (feof(lf->f)) return NULL;
  573. *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */
  574. }
  575. return lf->buff;
  576. }
  577. static int errfile (lua_State *L, const char *what, int fnameindex) {
  578. const char *serr = strerror(errno);
  579. const char *filename = lua_tostring(L, fnameindex) + 1;
  580. lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
  581. lua_remove(L, fnameindex);
  582. return LUA_ERRFILE;
  583. }
  584. static int skipBOM (LoadF *lf) {
  585. const char *p = "\xEF\xBB\xBF"; /* UTF-8 BOM mark */
  586. int c;
  587. lf->n = 0;
  588. do {
  589. c = getc(lf->f);
  590. if (c == EOF || c != *(const unsigned char *)p++) return c;
  591. lf->buff[lf->n++] = c; /* to be read by the parser */
  592. } while (*p != '\0');
  593. lf->n = 0; /* prefix matched; discard it */
  594. return getc(lf->f); /* return next character */
  595. }
  596. /*
  597. ** reads the first character of file 'f' and skips an optional BOM mark
  598. ** in its beginning plus its first line if it starts with '#'. Returns
  599. ** true if it skipped the first line. In any case, '*cp' has the
  600. ** first "valid" character of the file (after the optional BOM and
  601. ** a first-line comment).
  602. */
  603. static int skipcomment (LoadF *lf, int *cp) {
  604. int c = *cp = skipBOM(lf);
  605. if (c == '#') { /* first line is a comment (Unix exec. file)? */
  606. do { /* skip first line */
  607. c = getc(lf->f);
  608. } while (c != EOF && c != '\n');
  609. *cp = getc(lf->f); /* skip end-of-line, if present */
  610. return 1; /* there was a comment */
  611. }
  612. else return 0; /* no comment */
  613. }
  614. LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
  615. const char *mode) {
  616. LoadF lf;
  617. int status, readstatus;
  618. int c;
  619. int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */
  620. if (filename == NULL) {
  621. lua_pushliteral(L, "=stdin");
  622. lf.f = stdin;
  623. }
  624. else {
  625. lua_pushfstring(L, "@%s", filename);
  626. lf.f = fopen(filename, "r");
  627. if (lf.f == NULL) return errfile(L, "open", fnameindex);
  628. }
  629. if (skipcomment(&lf, &c)) /* read initial portion */
  630. lf.buff[lf.n++] = '\n'; /* add line to correct line numbers */
  631. if (c == LUA_SIGNATURE[0] && filename) { /* binary file? */
  632. lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */
  633. if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
  634. skipcomment(&lf, &c); /* re-read initial portion */
  635. }
  636. if (c != EOF)
  637. lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */
  638. status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
  639. readstatus = ferror(lf.f);
  640. if (filename) fclose(lf.f); /* close file (even in case of errors) */
  641. if (readstatus) {
  642. lua_settop(L, fnameindex); /* ignore results from 'lua_load' */
  643. return errfile(L, "read", fnameindex);
  644. }
  645. lua_remove(L, fnameindex);
  646. return status;
  647. }
  648. typedef struct LoadS {
  649. const char *s;
  650. size_t size;
  651. } LoadS;
  652. static const char *getS (lua_State *L, void *ud, size_t *size) {
  653. LoadS *ls = (LoadS *)ud;
  654. (void)L; /* not used */
  655. if (ls->size == 0) return NULL;
  656. *size = ls->size;
  657. ls->size = 0;
  658. return ls->s;
  659. }
  660. LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size,
  661. const char *name, const char *mode) {
  662. LoadS ls;
  663. ls.s = buff;
  664. ls.size = size;
  665. return lua_load(L, getS, &ls, name, mode);
  666. }
  667. LUALIB_API int luaL_loadstring (lua_State *L, const char *s) {
  668. return luaL_loadbuffer(L, s, strlen(s), s);
  669. }
  670. /* }====================================================== */
  671. LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
  672. if (!lua_getmetatable(L, obj)) /* no metatable? */
  673. return LUA_TNIL;
  674. else {
  675. int tt;
  676. lua_pushstring(L, event);
  677. tt = lua_rawget(L, -2);
  678. if (tt == LUA_TNIL) /* is metafield nil? */
  679. lua_pop(L, 2); /* remove metatable and metafield */
  680. else
  681. lua_remove(L, -2); /* remove only metatable */
  682. return tt; /* return metafield type */
  683. }
  684. }
  685. LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
  686. obj = lua_absindex(L, obj);
  687. if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */
  688. return 0;
  689. lua_pushvalue(L, obj);
  690. lua_call(L, 1, 1);
  691. return 1;
  692. }
  693. LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
  694. lua_Integer l;
  695. int isnum;
  696. lua_len(L, idx);
  697. l = lua_tointegerx(L, -1, &isnum);
  698. if (!isnum)
  699. luaL_error(L, "object length is not an integer");
  700. lua_pop(L, 1); /* remove object */
  701. return l;
  702. }
  703. LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
  704. if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */
  705. if (!lua_isstring(L, -1))
  706. luaL_error(L, "'__tostring' must return a string");
  707. }
  708. else {
  709. switch (lua_type(L, idx)) {
  710. case LUA_TNUMBER: {
  711. if (lua_isinteger(L, idx))
  712. lua_pushfstring(L, "%I", (LUAI_UACINT)lua_tointeger(L, idx));
  713. else
  714. lua_pushfstring(L, "%f", (LUAI_UACNUMBER)lua_tonumber(L, idx));
  715. break;
  716. }
  717. case LUA_TSTRING:
  718. lua_pushvalue(L, idx);
  719. break;
  720. case LUA_TBOOLEAN:
  721. lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false"));
  722. break;
  723. case LUA_TNIL:
  724. lua_pushliteral(L, "nil");
  725. break;
  726. default: {
  727. int tt = luaL_getmetafield(L, idx, "__name"); /* try name */
  728. const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) :
  729. luaL_typename(L, idx);
  730. lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx));
  731. if (tt != LUA_TNIL)
  732. lua_remove(L, -2); /* remove '__name' */
  733. break;
  734. }
  735. }
  736. }
  737. return lua_tolstring(L, -1, len);
  738. }
  739. /*
  740. ** set functions from list 'l' into table at top - 'nup'; each
  741. ** function gets the 'nup' elements at the top as upvalues.
  742. ** Returns with only the table at the stack.
  743. */
  744. LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
  745. luaL_checkstack(L, nup, "too many upvalues");
  746. for (; l->name != NULL; l++) { /* fill the table with given functions */
  747. if (l->func == NULL) /* place holder? */
  748. lua_pushboolean(L, 0);
  749. else {
  750. int i;
  751. for (i = 0; i < nup; i++) /* copy upvalues to the top */
  752. lua_pushvalue(L, -nup);
  753. lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */
  754. }
  755. lua_setfield(L, -(nup + 2), l->name);
  756. }
  757. lua_pop(L, nup); /* remove upvalues */
  758. }
  759. /*
  760. ** ensure that stack[idx][fname] has a table and push that table
  761. ** into the stack
  762. */
  763. LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
  764. if (lua_getfield(L, idx, fname) == LUA_TTABLE)
  765. return 1; /* table already there */
  766. else {
  767. lua_pop(L, 1); /* remove previous result */
  768. idx = lua_absindex(L, idx);
  769. lua_newtable(L);
  770. lua_pushvalue(L, -1); /* copy to be left at top */
  771. lua_setfield(L, idx, fname); /* assign new table to field */
  772. return 0; /* false, because did not find table there */
  773. }
  774. }
  775. /*
  776. ** Stripped-down 'require': After checking "loaded" table, calls 'openf'
  777. ** to open a module, registers the result in 'package.loaded' table and,
  778. ** if 'glb' is true, also registers the result in the global table.
  779. ** Leaves resulting module on the top.
  780. */
  781. LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
  782. lua_CFunction openf, int glb) {
  783. luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
  784. lua_getfield(L, -1, modname); /* LOADED[modname] */
  785. if (!lua_toboolean(L, -1)) { /* package not already loaded? */
  786. lua_pop(L, 1); /* remove field */
  787. lua_pushcfunction(L, openf);
  788. lua_pushstring(L, modname); /* argument to open function */
  789. lua_call(L, 1, 1); /* call 'openf' to open module */
  790. lua_pushvalue(L, -1); /* make copy of module (call result) */
  791. lua_setfield(L, -3, modname); /* LOADED[modname] = module */
  792. }
  793. lua_remove(L, -2); /* remove LOADED table */
  794. if (glb) {
  795. lua_pushvalue(L, -1); /* copy of module */
  796. lua_setglobal(L, modname); /* _G[modname] = module */
  797. }
  798. }
  799. LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s,
  800. const char *p, const char *r) {
  801. const char *wild;
  802. size_t l = strlen(p);
  803. while ((wild = strstr(s, p)) != NULL) {
  804. luaL_addlstring(b, s, wild - s); /* push prefix */
  805. luaL_addstring(b, r); /* push replacement in place of pattern */
  806. s = wild + l; /* continue after 'p' */
  807. }
  808. luaL_addstring(b, s); /* push last suffix */
  809. }
  810. LUALIB_API const char *luaL_gsub (lua_State *L, const char *s,
  811. const char *p, const char *r) {
  812. luaL_Buffer b;
  813. luaL_buffinit(L, &b);
  814. luaL_addgsub(&b, s, p, r);
  815. luaL_pushresult(&b);
  816. return lua_tostring(L, -1);
  817. }
  818. static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
  819. (void)ud; (void)osize; /* not used */
  820. if (nsize == 0) {
  821. free(ptr);
  822. return NULL;
  823. }
  824. else
  825. return realloc(ptr, nsize);
  826. }
  827. static int panic (lua_State *L) {
  828. const char *msg = lua_tostring(L, -1);
  829. if (msg == NULL) msg = "error object is not a string";
  830. lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
  831. msg);
  832. return 0; /* return to Lua to abort */
  833. }
  834. /*
  835. ** Warning functions:
  836. ** warnfoff: warning system is off
  837. ** warnfon: ready to start a new message
  838. ** warnfcont: previous message is to be continued
  839. */
  840. static void warnfoff (void *ud, const char *message, int tocont);
  841. static void warnfon (void *ud, const char *message, int tocont);
  842. static void warnfcont (void *ud, const char *message, int tocont);
  843. /*
  844. ** Check whether message is a control message. If so, execute the
  845. ** control or ignore it if unknown.
  846. */
  847. static int checkcontrol (lua_State *L, const char *message, int tocont) {
  848. if (tocont || *(message++) != '@') /* not a control message? */
  849. return 0;
  850. else {
  851. if (strcmp(message, "off") == 0)
  852. lua_setwarnf(L, warnfoff, L); /* turn warnings off */
  853. else if (strcmp(message, "on") == 0)
  854. lua_setwarnf(L, warnfon, L); /* turn warnings on */
  855. return 1; /* it was a control message */
  856. }
  857. }
  858. static void warnfoff (void *ud, const char *message, int tocont) {
  859. checkcontrol((lua_State *)ud, message, tocont);
  860. }
  861. /*
  862. ** Writes the message and handle 'tocont', finishing the message
  863. ** if needed and setting the next warn function.
  864. */
  865. static void warnfcont (void *ud, const char *message, int tocont) {
  866. lua_State *L = (lua_State *)ud;
  867. lua_writestringerror("%s", message); /* write message */
  868. if (tocont) /* not the last part? */
  869. lua_setwarnf(L, warnfcont, L); /* to be continued */
  870. else { /* last part */
  871. lua_writestringerror("%s", "\n"); /* finish message with end-of-line */
  872. lua_setwarnf(L, warnfon, L); /* next call is a new message */
  873. }
  874. }
  875. static void warnfon (void *ud, const char *message, int tocont) {
  876. if (checkcontrol((lua_State *)ud, message, tocont)) /* control message? */
  877. return; /* nothing else to be done */
  878. lua_writestringerror("%s", "Lua warning: "); /* start a new warning */
  879. warnfcont(ud, message, tocont); /* finish processing */
  880. }
  881. LUALIB_API lua_State *luaL_newstate (void) {
  882. lua_State *L = lua_newstate(l_alloc, NULL);
  883. if (L) {
  884. lua_atpanic(L, &panic);
  885. lua_setwarnf(L, warnfoff, L); /* default is warnings off */
  886. }
  887. return L;
  888. }
  889. LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
  890. lua_Number v = lua_version(L);
  891. if (sz != LUAL_NUMSIZES) /* check numeric types */
  892. luaL_error(L, "core and library have incompatible numeric types");
  893. else if (v != ver)
  894. luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
  895. (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)v);
  896. }